We are investigating the transport of amino acids which are directly or indirectly incorporated into glutathione (G) and ophthalmic acid (OA) in the ocular lens. Different systems of transport are involved for the substituent amino acids, though there is some overlap in affinities for the various transporters. The incorporation of cysteine into G and of alpha-aminobutyrate into OA will be examined with the objectives of ascertaining the turnover of the tripeptides and learning whether the levels of these amino acids are rate-limiting in biosynthesis. Their competition for gamma-glutamylcysteine synthetase is also to be evaluated. We intend to study the effect of 2-mercaptoethylamine (cysteamine) on synthesis of G in the lens culture. If the inhibitor of gamma-glutamyl synthetase is effective, analysis of catabolism of G will be facilitated. Protein-free extracts of the lens are to be chromatographed on anion exhange columns in an attempt to achieve better resolution of the lenticular acidic amino acids and peptides which are of interest. BIBLIOGRAPHIC REFERENCE: Kern, H. L., and C.-K. Ho. Transport of dicarboxylic amino acids in the rat lens. Ophthal. Res. 6, 166, 1974.